1. Field of the Invention
The present invention relates to a method for manufacturing a honeycomb structure.
2. Discussion of the Background
Exhaust gases discharged from conventional internal combustion engines such as a diesel engine contain particulate matter (hereinafter, also referred to as PM). In recent years, the PM has raised serious problems because it is harmful to the environment and the human body.
For this reason, various honeycomb filters such as a honeycomb filter including a porous ceramic honeycomb structure have been proposed as filters that capture PM in exhaust gases and purify the exhaust gases.
As such a honeycomb structure, there has been disclosed a honeycomb structure in which a plurality of filters including a porous ceramic sintered body are integrated by bonding peripheral faces of the filters with one another with a sealing material layer (adhesive layer) interposed therebetween (see, for example, JP-A 2001-162121).
A honeycomb structure of this kind can be manufactured as follows.
First, a ceramic powder, a binder, a dispersant solution and the like are mixed to prepare a wet mixture.
Next, the wet mixture is extrusion-molded, and the extrusion-molded body is cut into a predetermined length to form a honeycomb molded body.
Thereafter, a plug material paste is injected to a predetermined end of each cell of the honeycomb molded body to seal each cell at either one end. Next, the honeycomb molded body with the plug material paste filled therein is degreased and fired to form honeycomb fired bodies to be used as a filter.
Next, a plurality of the honeycomb fired bodies are combined with one another with a sealing material layer (adhesive layer) interposed therebetween to form an aggregated body of the honeycomb fired bodies. Thereafter, if necessary, the periphery of the aggregated body of the honeycomb fired bodies is cut and a coat layer is formed on the periphery of the aggregated body to manufacture a honeycomb structure.
Further, as such a honeycomb structure used as a catalyst carrier, a honeycomb structure in which porous ceramic units each containing a first inorganic material (for example, ceramic particles), a second inorganic material (for example, inorganic fibers or ceramic particles having a larger particle diameter) and an inorganic binder are joined to one another with a sealing material interposed therebetween has been disclosed (see, for example, WO 2005/063653 A1).
The contents of JP-A 2001-162121 and WO 2005/063653 A1 are incorporated herein by reference in their entirety.